It’s been nearly a week since Special Counsel Robert Mueller’s plea agreement with former Donald Trump National Security Adviser Michael Flynn became official, but the details of that deal are still leaking out. Today a new clause in the deal surfaced publicly, which reveals additional requirements for Flynn whose sole purpose is to prevent Trump from sabotaging things. This led one respected legal scholar to simply declare “Checkmate!”

Here’s how Harvard Law Professor Laurence Tribe summed up the latest news: “Flynn’s plea deal, unlike nearly all other plea deals, includes a sweeping, open-ended pledge by Flynn to cooperate fully with any state & local prosecutors Mueller might designate — which defangs Trump’s power to shield himself by firing or pardoning people. Checkmate!” (link). There are two specific things here at play.

First, let’s say that Trump decides to pardon Flynn on all federal charges, in a belated attempt at preventing Flynn from continuing to rat him out. Flynn would still be at the mercy of state level prosecutors such as New York Attorney General Eric Schneiderman, who could either charge Flynn based on his confession, or force Flynn to cooperate in any state-level charges that are brought against Trump. Second, even if Trump fires Mueller, Flynn will still be locked into helping to take down Trump on a state level. It seems a given that any additional high ranking targets who cut a deal will be subject to this same clause.

In short, this means that Donald Trump can’t get very far by trying to pardon anyone, or by trying to fire Robert Mueller. It was already too late for that. Trump would have needed to pardon Flynn before his plea deal for it to have helped him much, and Trump would have needed to fire Mueller months ago back when he would have had more political muscle for trying to pull it off. But this plea deal clause helps to wall Trump in even further. It’s simply too late. The game isn’t finished being played yet, but it is indeed checkmate, as he’s going to lose.